I can't find any information on initalizing a couch db. What's the best method of initializing and creating the map and view functions for couchdb at deployment?
I have a node server which will access a couchdb. Should I just create the http calls necessary to create the proper logic on couchdb from my node server or is there a better way handling the initialization of the db?
EDIT: Also is there any good open source projects that I can take examples from?
I'm not sure your question is clear. Remember that CouchDB is schemaless, so, at startup, there probably isn't anything (ie, documents) on which to base view functions.
If you mean a helper to setup a design document with attachments and the like, in addition to the other answers, have a look at Kanso (http://kan.so). If you're comfortable with Node, you'll find it friendly.
If, on the other hand, you're looking for something to analyze existing docs in a CouchDB and guess at good views, I've haven't come across that yet.
One possibility would be to use erica.
Related
I have a web server which is made specifically for an app. Some of the services get very complex in terms of calling a lot of functions across multiple services and each of them querying multiple models. Would it be good idea to save the queried documents of each request in AsyncLocalStorage to reduce the time taken for querying?
So, I would check if document is present in ALS if yes then use it else fetch and save it there before using.
I tried to find references related to this but didn't find anything. Which led me to think maybe it is not such a good idea after all. But then querying the same document again and again over different services doesn't make sense either.
I have been reading docs and articles on pouchdb/couchdb/cloudant. I am not able to create this simple architecture in my head. I need help!
So there are many users on the app. Each user has a separate database (which I read is the approach in pouch/couch/cloudant setup).
Now lets just focus on a single user. This user has some remote data already present on our server(couchdb). He has 3 separate docs stored.
He accesses docs 1 and docs 2 from browser 1. And docs 2 and docs 3 from browser 2.
Content in both the browsers must be in sync.
Should I be using Sync api of pouchdb? But as I read, it sync's the whole database. How can I use this api to sync only a subset of the central database. Is filtered replication answer here?
And also I don't want to push both the docs in a single call. He can access docs as he needs.
What is the correct approach to implement this logic with pouch/couch databases. If you can explain with a little code, that will be great. I just need basic ideas.
Is this kind of problem easily solvable in upcoming releases of CouchDB 2.0 and PouchDB-find.
Thanks a lot!
If you take a look at the PouchDB documentation, you should see the options.doc_ids. This parameter let you setup a replication on certain document ids. In your scenario, this would be solving your problem.
I'm currently involved in a app project, and I'm incharge of setting up the backend.
What i'm use to using is a MYSQL database + php for cleaning and managing the data sent to and fro the front end, which I have much more experience in. However, because of certain preferences of my bosses, on this project I've found myself looking at IBMs Bluemix and Cloudant software. Cloudant is a NoSQL database(like CouchDB) and my experience regarding noSQL is severely lacking. All I've mananged to do so far is to create a few JSON documents, and some basic views
What I need to figure out is how to perform the CRUD(create,read,update,delete) actions on a NoSQL database, or at least what it would look like.
In addition to this, I need to know if there are ways to implement security measures(implement security and anti-hacking functions) on a NoSQL database without an external source, or will I need to learn how to reroute the data through some sort of php function first, if i want it cleaned, before sending it to the Cloudant server where my database sits.
Let me know if my attempt to explain my problem is lacking in clarity. I'll try my best to state a different way, if need be.
Generally speaking, there is nothing equivalent to an ANSI to NoSQL databases. In other words, NoSQL databases are not as standardized as SQL databases. All standards are starting to appear. You can think of it as a technology still in the making.
What you have in general is an API with methods such as put_record or delete_record, or a REST interface that is logically equivalent. Also, in general you CRUD the whole record, not parts of the record.
Take a look at the reference: Cloudant - Reading and Writing
Having that said, in your case I would recommend abstracting away from the specific implementation of the NoSQL you want to use if you care about avoiding vendor lock-in. So I would suggest you to wrap CRUD functions using PHP functions that later can be replaced if you want to change the NoSQL database flavor.
This approach has the additional advantage to provide an abstraction for you to implement your own security. Some important NoSQL databases have no concept of multi-tenancy or just implemented that. Again, it is a technology in the making.
When your mindset is the relational one, you tend to think of the database as something that will help you guarantee data consistency as much as possible. But NoSQL databases are not like that. Think of them as a simple repository of documents (in a JSON or XML structure, for instance), without cross references.
Then the obvious question is perhaps: why would anyone want such a thing? One of the possible answers is because NoSQL databases may hold an aggregate of consolidated data. You can then retrieve aggregates to save time reprocessing or re-retrieving data unnecessarily.
As for security, most (if no all) NoSQL databases have some pretty good authentication mechanisms.
I've been able to sync data from my cloudant instance to my nodejs based pouchdb, however I need to setup a secondary search index and therefore I created a view on the couchdb instance however I am unable to see it in my synced pouchdb instance.
I see it in cloudant, in all documents, however after syncing and calling alldocs on pouchdb, it's not there. Also, i'm using the pouchdb-find plugin and I can't reference the secondary index search fields. Of course from pouchdb if if set the secondary index, it works fine.
Am I missing something? Does sync not replicate design docs in PouchDB? If not, what's the best way to create a persistent secondary index?
Any good docs for this? (Nolan....?) Speaking of docs, or support, is there an IRC room or some other live support for couchdb from the user community?
Thanks for your attention,
Paul
pouchdb-find is a reimplementation of Cloudant Query Language, not their search index (which is what I think you're talking about). It's also not done; I've only written about half of the operators. :) You may also want to try the pouchdb-quick-search plugin, which is for full-text search.
In general, the advice I usually give people is to not sync design documents at all – just replicate using a filter to avoid syncing design docs. Then you can create design documents that are optimized for whatever platform you happen to be on (PouchDB, CouchDB, Cloudant, the various PouchDB plugins, etc.).
And yeah, we are usually pretty responsive inside of the IRC channel and on the mailing list, but it's a small operation because we aren't sponsored by Cloudant or Couchbase or anybody. The core PouchDB team are all hobbyists. :)
Maybe this is stupid but, does the user that access couch has the admin role? Only admins can see and edit design documents.
I am looking at Couch Db and I saw Ektorp that presents a JPA like interface for database. However I see that there are examples that how to make query at JavaScript. I didn't understand how the system work.
Do I query a database from web tier without a middle tier? How can security be done with that?
CouchDB uses javascript to define map and reduce functions for it's views. Ektorp is simply providing you a convenient way to create those functions that will be used by couchdb. You might want to read the couchdb wiki page on views:
http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views
Just because the views are javascript, does not imply that you have to create the views from a 'web tier'.
In terms of architecture, you have a couple of options. You can use a traditional three tier approach with a java front end, and in your middle tier call couchdb with ektorp. Then you are in full control of security.
You can also go with what is coming to be known as the 2.1 tier model, where users interact directly with couchdb, mainly with a couchapp. You can then provide support services that listen to the changes feed. I have done this with ektorp and it works very well. Other have used node.js. It is a different way of thinking, but it can work. You can read a fun post about this model here:
http://markmail.org/thread/cfw7f3ef75aoqzin
Anyway, I just wanted to provide you with possible options in how you 'tier' your architecture.